During the time of the Old Covenant, men were not saved by keeping of the Law. Men were saved by faith.
Romans 4:3 “For what saith the scripture? Abraham believed God, and it was counted unto him for righteousness.” Genesis 15:6.
This faith caused them to obey God. This is a positive statement.
Genesis 26:5 “Because that Abraham obeyed my voice, and kept my charge, my commandments, my statutes, and my laws.”
There is no difference today. The old covenant is the same as the new covenant with one difference.
Hebrews 10:16 “This is the covenant that I will make with them after those days, saith the Lord, I will put my laws into their hearts, and in their minds will I write them”. Jeremiah 31:31-33, Hebrews 8:8-10.
God’s Law, which is Christ’s Law, is now written on the heart. If you have this extra feature, then you are a physical Israelite as scripture plainly teaches.